Power supply

ABSTRACT

A system includes one or more constant “on” outlets, one or more controlled outlets, a two-part power supply, and accompanying circuitry. Other embodiments are also disclosed herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser. No. 61/047,070, filed on Apr. 22, 2008, and U.S. Provisional Application Ser. No. 61/155,468, filed on Feb. 25, 2009, both of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

Subject matter described herein relates to power supply devices, and more particularly to the internal power management of power supplies for electronic devices.

BACKGROUND

Electronic devices of all types have become more and more common in everyday life. Electronic devices include non-portable devices as well as portable devices. Examples of non-portable electronic devices include wired telephones, routers (wired and wireless), wireless access points (WAPs) and the like. Examples of portable electronic devices include cellular phones, personal data assistants (PDAs), combination cellular phone and PDAs (e.g., a Blackberry® device available from Research in Motion (RIM®) of Ontario, Canada), cellular phone accessories (e.g., a Bluetooth® enabled wireless headset), MP3 (Moving Pictures Experts Group-1 Audio Layer 3) players (e.g., an iPod® device by Apple Inc. (Apple®) of Cupertino, Calif.), compact disc (CD) players, and digital video disk (DVD) players. Along with the positive benefits of use of such devices comes the requirement to power the devices and/or communicate with them. Power supplies use power even when not supplying power to electronic devices that are in electrical communication with the power supplies. Reducing the administrative power consumption of the power supplies for such devices can prove difficult.

BRIEF DESCRIPTION OF THE DRAWINGS

To facilitate further description of the embodiments, the following drawings are provided in which:

FIG. 1 is a block diagram illustrating an improved power supply including aspects of the subject matter described herein;

FIG. 2 is a block diagram illustrating an embodiment of the improved power supply of FIG. 1 including aspects of the subject matter described herein;

FIG. 3 is a block diagram illustrating another embodiment of the improved power supply of FIG. 1 including aspects of the subject matter described herein;

FIG. 4 is a block diagram illustrating yet another embodiment of the improved power supply of FIG. 1 including aspects of the subject matter described herein;

FIG. 5 is a schematic diagram illustrating an embodiment of a metal oxide varistor (MOV) protection circuit portion of FIGS. 2-4 including aspects of the subject matter described herein;

FIG. 6 is a schematic diagram illustrating an embodiment of the improved power supply of FIG. 2 that includes aspects of the subject matter described herein;

FIG. 7 is a schematic diagram illustrating an embodiment of the improved power supply of FIG. 3 that includes aspects of the subject matter described herein;

FIG. 8 is a schematic diagram illustrating an embodiment of the improved power supply of FIG. 4 that includes aspects of the subject matter described herein;

FIG. 9 is a schematic diagram illustrating another embodiment of the improved power supply of FIG. 2 that includes aspects of the subject matter described herein; and

FIG. 10 is a block diagram illustrating a method for providing improved power that includes aspects of the subject matter described herein.

The phrase “subject matter described herein” refers to subject matter described in the Detailed Description unless the context clearly indicates otherwise. The term “aspects” is to be read as “at least one aspect.” Identifying aspects of the subject matter described in the Detailed Description is not intended to identify key or essential features of the claimed subject matter. The aspects described above and other aspects of the subject matter described herein are illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate substantially similar elements.

For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring aspects of the subject matter described herein. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the subject matter described herein.

The terms “first,” “second,” “third,” “fourth,” and the like in the Detailed Description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the subject matter described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the Detailed Description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the aspects of the subject matter described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. The term “on,” as used herein, is defined as on, at, or otherwise substantially adjacent to or next to or over.

The terms “couple,” “coupled,” “couples,” “coupling,” and the like should be broadly understood and refer to connecting two or more elements or signals, electrically, mechanically, or otherwise, either directly or indirectly through intervening circuitry and/or elements. Two or more electrical elements may be electrically coupled, either direct or indirectly, but not be mechanically coupled; two or more mechanical elements may be mechanically coupled, either direct or indirectly, but not be electrically coupled; two or more electrical elements may be mechanically coupled, directly or indirectly, but not be electrically coupled. Coupling (whether only mechanical, only electrical, both, or otherwise) may be for any length of time, e.g., permanent or semi-permanent or only for an instant.

“Electrical coupling” and the like should be broadly understood and include coupling involving any electrical signal, whether a power signal, a data signal, and/or other types or combinations of electrical signals. “Mechanical coupling” and the like should be broadly understood and include mechanical coupling of all types.

The absence of the word “removably,” “removable,” and the like near the word “coupled,” and the like does not mean that the coupling, etc. in question is or is not removable. For example, the recitation of a clip being coupled to an outer casing does not mean that the clip cannot be removed (readily or otherwise) from, or that it is permanently connected to, the outer casing.

DETAILED DESCRIPTION OF EXAMPLES OF EMBODIMENTS

FIG. 1 is a block diagram illustrating an embodiment of an exemplary system for providing a multi-outlet controlled power strip including multiple inputs, surge protection and incorporating an improved power supply. FIG. 1 includes power strip 100 (also called a relocatable power tap (RPT)) including control circuitry 110, power plug 120, constant “on” outlet(s) 130, command input device 140 and controlled outlet(s) 150. Control circuitry 110 is a circuit configured to receive power signals and disperse power signals to constant “on” outlet(s) 130 and possibly command input device 140 if so configured, and further disperse power signals to controlled outlet(s) 150 based on input received from command input device 140. Control circuitry 110 can include some or all the improved power supply circuitry that is detailed in FIGS. 2-4 as well as in FIGS. 6-8 below. In some embodiments, control circuitry 110 additionally includes protection circuitry. Protection circuitry is described in FIG. 2 and specifically detailed in FIG. 5, below.

Power plug 120 is an electrical conduit that is physically coupled to and in electrical communication with control circuitry 110. Power plug 120 is configured to pass a power signal received from a power source to control circuitry 110 when power plug 120 is physically coupled to and in electrical communication with a power source (not shown). Constant “on” outlet(s) 130 are a power outlet that are physically coupled to and in constant electrical communication with control circuitry 110 and are further configured to pass a power signal received from control circuitry 110 to any device with which it is in electrical communication.

Command input device 140 is any input device that is physically coupled to and in electrical communication with control circuitry 110 and is further configured to pass a command signal to control circuitry 110 based on a received command signal or command action that command input device 140 received previously. Controlled outlet(s) 150 are a power outlet that are physically coupled to and in controlled electrical communication with control circuitry 110 and are further selectively configured to pass a power signal received from control circuitry 110 to any device with which it is in electrical communication. Command input device 140 can be implemented as any suitable command input device, such as, for example a master outlet as part of a master/slave power strip configuration providing a control signal to control circuitry 110 by drawing current from control circuitry 110, a receiver device providing a control signal to control circuitry 110, a sensing device providing a control signal to control circuitry 110, and the like. Examples of a receiver device providing a control signal to control circuitry 110 include a radio frequency (RF) receiver, a light emitting diode (LED) receiver, a wireless networked receiver, a short range wireless receiver that is part of a personal area network (PAN), and the like.

In operation, when power plug 120 is operably coupled to and in electrical communication with an appropriate power source (e.g., an alternating current (a.c.) or other power outlet fixture), power becomes available to constant “on” outlet(s) 130 and command input device 140, as appropriate. At this time, if command input device 140 has not provided an appropriate command signal to control circuitry 110, power is NOT available to controlled outlet(s) 150, and any device(s) operably coupled to and in electrical communication with controlled outlet(s) 150 will NOT receive any current or power. Control circuitry 110 is configured to detect when a control signal is received from command input device 140. In an example, when command input device 140 provides an “on” control signal to control circuitry 110, control circuitry 110 will provide power to controlled outlet(s) 150 thereby providing current and/or power to any devices coupled to and in electrical communication with controlled outlet(s) 150. Similarly, when command input device 140 provides an “off” control signal to control circuitry 110 and then changes the control signal to an “on” control signal, control circuitry 110 will provide power to controlled outlet(s) 150 thereby providing current and/or power to any devices coupled to and in electrical communication with controlled outlet(s) 150.

The exemplary configuration illustrated in FIG. 1 allows a user, via constant “on” outlet(s) 130, the flexibility to assign certain devices (e.g., a clock, cable/satellite receiver, etc.) to be supplied with constant power as well as determine when other devices receive power. Additionally, the configuration allows a user, via command input device 140 and controlled outlet(s) 150, to control when power is supplied to a primary device (e.g., a personal computer, such as, a laptop or desktop computer) as well as or in addition to secondary devices, such as, peripherals (e.g., printers, scanners, etc.).

FIG. 2 is a block diagram illustrating an embodiment of an exemplary system for providing a multi-outlet controlled power strip including surge protection and incorporating an improved power supply. The power strip 200 in FIG. 2 is a detailed view of power strip 100 of FIG. 1. As shown in FIG. 2, power strip 200 includes: control circuitry 110, power plug 120, constant “on” outlet(s) 130, command input device 140 (configured as a master outlet) and controlled outlet(s) 150. Control circuitry 110 includes metal oxide varistors (MOV) protection circuit 260, hi-power (HI PWR) circuit 270, low-power (LO PWR) circuit 280 and control circuit 290. Command input device 140 includes master outlet 240, sensing (SENSE) circuit 242 amplification (AMP) circuit 244. Elements numbered as in FIG. 1 function in a substantially similarly way.

MOV protection circuit 260 has an input and an output. The input of MOV protection circuit 260 is electrically coupled and in communication with power plug 120. The output of MOV protection circuit 260 is electrically coupled and in communication with constant “on” outlet(s) 130, master outlet 240 portion of command input device 140, HI PWR circuit 270, LO PWR circuit 280, and control circuit 290. MOV protection circuit 260 receives a power signal from power plug 120 and provides protected power signals to constant “on” outlet(s) 130, command input device 140, HI PWR circuit 270, LO PWR circuit 280, and control circuit 290. An embodiment of MOV protection circuit 260 is described in FIG. 5, below. In operation, MOV protection circuit 260 provides one or more of the following: conditions the received power signal to, among other things, reduce incoming radiated and conducted high frequency signals and noise; reduces the amplitude of incoming overvoltage spikes/surges; provides protection for power strip 200 from defective MOV units within MOV protection circuit 260; and determines the presence of a ground connection as well as communicate that information to a user. In short, MOV protection circuit 260 provides protected power to all other circuitry and outlets within power strip 200.

HI PWR circuit 270 has an input and an output. The input of HI PWR circuit 270 is electrically coupled and in communication with MOV protection circuit 260, constant “on” outlet(s) 130, master outlet 240 portion of command input device 140 and LO PWR circuit 280. The output of HI PWR circuit 270 is electrically coupled and in communication with control circuit 290. LO PWR circuit 280 has an input and an output. The input of LO PWR circuit 280 is electrically coupled and in communication with MOV protection circuit 260, constant “on” outlet(s) 230, master outlet 240 portion of command input device 140 and HI PWR circuit 270. The output of LO PWR circuit 280 is electrically coupled and in communication with AMP circuit 244 portion of command input device 140. HI PWR circuit 270 and LO PWR circuit 280 each receive a protected alternating current (AC) power signal from MOV protection circuit 260 and generate different levels of low voltage power for the internal circuitry of power strip 200. HI PWR circuit 270 and LO PWR circuit 280 efficiently convert line AC power to the voltages required to operate control circuit 290 and AMP circuit 244, respectively. HI PWR circuit 270 and LO PWR circuit 280 can be optimized to take advantage of the most efficient power levels to run the internal circuitry of power strip 200. In operation, LO PWR circuit 280 supplies real power to AMP circuit 244, and HI PWR circuit 270 supplies real power to the control circuit 290 allowing for efficient use of power. The uniqueness of this approach as compared to a more traditional single power supply approach is that a power savings as high as 4 to 1 can be achieved over the traditional method. An embodiment of HI PWR circuit 270 and LO PWR circuit 280 and the advantages of utilizing this configuration are further described in FIGS. 6-8, below.

Control circuit 290 has an input and an output. The input of control circuit 290 is electrically coupled and in separate communication with MOV protection circuit 260, HI PWR circuit 270 and AMP circuit 244 portion of command input device 140. The output of control circuit 290 is electrically coupled and in communication with controlled outlet(s) 150. Control circuit 290 receives a real power signal from HI PWR circuit 270 and additionally receives a driving signal from AMP circuit 244 when a device that is plugged into master outlet 240 portion of command input device 140 is drawing enough power to be active. When control circuit 290 receives the driving signal from AMP circuit 244, control circuit 290 allows current to flow between MOV protection circuit 260 and controlled outlet(s) 150.

SENSE circuit 242 of command input device 140 includes an input and an output. The input of SENSE circuit 242 is electrically coupled and in communication with master outlet 240 of command input device 140. The output of SENSE circuit 242 is electrically coupled and in communication with AMP circuit 244 of command input device 140. SENSE circuit 242 monitors an output signal from master outlet 240 and provides a sensing signal to AMP circuit 244 indicating whether or not master outlet 240 is in use or is at least drawing current above a threshold or minimum predetermined valve. In operation, SENSE circuit 242 determines that master outlet 240 is drawing current when a device that is in electrical communication with master outlet 240 is drawing enough current to exceed a current threshold, such as drawing enough current to power the device in an “ON” state. In such a situation, SENSE circuit 242 produces a sensing signal in response to master outlet 240 drawing at least a predetermined amount of current and provides the created sensing signal to AMP circuit 244. In some embodiments, SENSE circuit 242 is powered by master outlet 240 because master outlet 240 is always “ON.” In such embodiments, current drawn from master outlet 240 that is monitored by SENSE circuit 242 can exclude the current (and power) that SENSE circuit 242 requires to run, and/or SENSE circuit 242 can be programmed (by hardware, software, or otherwise) or adjusted to account for the current (and power) that SENSE circuit 242 draws from master outlet 240.

AMP circuit 244 of command input device 140 includes an input and an output. The input of AMP circuit 244 is electrically coupled and in separate communication with SENSE circuit 242 and LO PWR circuit 280. The output of AMP circuit 244 is electrically coupled and in communication with control circuit 290. AMP circuit 244 receives a real power signal from LO PWR circuit 280 and additionally receives a sensing signal from SENSE circuit 242 that is based on the status of master outlet 240. AMP circuit 244 compares the signal received from SENSE circuit 242 to a threshold to determine whether master outlet 240 is “on.” If the signal received from SENSE circuit 242 equals or exceeds a threshold value, AMP circuit 244 generates a driving signal and provides the generated driving signal to control circuit 290.

In operation, power strip 200 enables a user to configure the power strip to utilize one primary device (e.g., a personal computer, such as, a laptop or desktop computer) in electrical communication with command input device 140 configured as a master/slave device to control when power is supplied to secondary devices, such as, peripherals (e.g., printers, scanners, etc.), desk lighting, and the like. In the same or a different embodiment, when a primary device is in “standby” state and is coupled to and in electrical communication with command input device 140 configured as a master/slave device, the primary device will receive current from master outlet 140, but the amount of current will be lower than when the device is in the “on” state. In this “standby” state, the device is receiving current at a level that is below a predetermined threshold level. In an example of this embodiment, power strip 200 treats the “standby” state similar to the “off” state such that, in both of these states: (1) master outlet 140 is not providing sufficient power or current to the primary device that is coupled to and in electrical communication with master outlet 140; and (2) control circuitry 110 will not provide power to controlled outlet(s) 150 and, therefore, will not provide current to any secondary devices coupled to and in electrical communication with controlled outlet(s) 150. An example of this embodiment can occur when the primary device is a television.

FIG. 3 is a block diagram illustrating another embodiment of an exemplary system for providing a multi-outlet controlled power strip including surge protection and incorporating an improved power supply. Power strip 300 in FIG. 3 is a detailed view of power strip 100 of FIG. 1. As shown in FIG. 3, power strip 300 includes: control circuitry 110, power plug 120, constant “on” outlet(s) 130, command input device 140 (configured as a wireless receiver) and controlled outlet(s) 150. Control circuitry 110 includes metal oxide varistors (MOV) protection circuit 260, hi-power (Ill PWR) circuit 270, low-power (LO PWR) circuit 280 and control circuit 290. Command input device 140 includes antenna 341, receiver circuit 343, logic circuit 345 and switch 348. Elements numbered as in FIGS. 1 and/or 2 function in a substantially similarly way. aspects of the subject matter described herein; Antenna 341 of command input device 140 includes an input and an output. The input of antenna 341 is wirelessly coupled and in communication with a transmitter (not shown). The output of antenna 341 is electrically coupled and in communication with receiver circuit 343 of command input device 140. Antenna 341 takes in radiated signals, which include information such as commands, in the form of waves of energy, known as electromagnetic signals, via cable, wire, ambient air, sensors or other mediums. Antenna 341 passes the received signals to receiver circuit 343. In one embodiment, antenna 341 can be a portion of the circuit board that is part of receiver 343, a wire antenna, or a commercially available antenna. Command input device 140 additionally includes switch 348. Switch 348 includes an input and an output. The input of switch 348 is configured to receive commands from a user. The output of switch 348 is electrically coupled to and in communication with logic circuit 345. In some embodiments, switch 348 is implemented as a manual switch. In other embodiments, switch 348 may be implemented as any other user input device capable of performing similar functionality including a mechanical switch in physical communication with logic circuit 345 and the like.

Receiver circuit 343 of command input device 140 includes an input and an output. The input of receiver circuit 343 is electrically coupled and in communication with antenna 341, and the output of receiver circuit 343 is electrically coupled and in communication with logic circuit 345. In one embodiment, receiver 343 is electrically coupled and in communication with LO PWR circuit 280. Receiver circuit 343 is configured to receive received signals from antenna 341, produce a command signal and pass the produced command signal to logic circuit 345. Receiver circuit 343 typically includes a tuner, a detector and an amplifier. The tuner resonates at a particular frequency and amplifies the resonant frequency. The detector detects the command signal within the received signal and extracts the command signal from the received signal. The amplifier amplifies the received command signal. In other embodiments, the same or different components provide substantially similar functionality and may combine functionality of the above described components. Receiver circuit 343 can be implemented as any suitable receiver circuit.

Logic circuit 345 of command input device 140 includes an input and an output. The input of logic circuit 345 is electrically coupled and in communication with receiver circuit 343, switch 348 and LO PWR circuit 280. The output of logic circuit 345 is electrically coupled and in communication with control circuit 290. Logic circuit 345 receives a received command signal from receiver circuit 343, generates an operational signal based on the logic within logic circuit 345 and passes the generated operational signal to control circuit 290. Logic circuit 345 can be implemented as any suitable logic circuit.

In operation, power strip 300 enables a user to wirelessly control the power strip to control when power is supplied to devices, such as, a personal computer or peripherals that are in electrical communication with controlled outlet(s) 150. In the same or a different embodiment, a user can wirelessly control power strip 300 using one or a number of electromagnetic methodologies, such as, for example infrared spectrum, wireless networking spectrum including personal area network (PAN) spectrum, radio frequency (RF) spectrum, light emitting diode (LED) spectrum, and the like. In one embodiment, power strip 300 enables a user to reduce power consumption of the devices in electrical communication with controlled outlet(s) 150 by allowing a user to completely shut power off to her deices.

FIG. 4 is a block diagram illustrating another embodiment of an exemplary system for providing a multi-outlet controlled power strip including surge protection and incorporating an improved power supply. The power strip 400 in FIG. 4 is a detailed view of power strip 100 of FIG. 1. As shown in FIG. 4, power strip 400 includes: control circuitry 110, power plug 120, constant “on” outlet(s) 130, command input device 140 (configured as a wireless receiver) and controlled outlet(s) 150. Control circuitry 110 includes metal oxide varistors (MOV) protection circuit 260, hi-power (HI PWR) circuit 270, low-power (LO PWR) circuit 280 and control circuit 290. Command input device 140 includes stimulus circuit 446 and microcontroller 447. Elements numbered as in FIGS. 1 and/or 2 function in a substantially similarly way.

Stimulus circuit 446 of command input device 140 includes an input and an output. The input of stimulus circuit 446 is configured to actively or passively sense/detect the presence of a required body within a specified area of the power strip incorporating stimulus circuit 446, such as, for example that of a user within a given distance of power strip 400. In one embodiment, stimulus circuit 446 receives power from microcontroller 347, and in a different embodiment (not shown), stimulus circuit 446 receives power from LO PWR circuit 280. The output of stimulus circuit 446 is electrically coupled and in communication with microcontroller 447 of command input device 140. In some embodiments, stimulus circuit 446 uses an active methodology by radiating energy waves into the area surrounding power strip 400, receiving reflected energy waves from surrounding objects and then producing a command signal which is passed to microcontroller 447. Examples of active energy waves that may be utilized by stimulus circuit 446 include ultrasonic spectrum, radio frequency (RF) spectrum, light emitting diode (LED) spectrum, and the like. In other embodiments, stimulus circuit 446 uses a passive methodology by sensing energy from the area surrounding power strip 400 and then producing a command signal which is passed to microcontroller 447. Examples of active energy waves that may be utilized by stimulus circuit 446 include infrared spectrum, audio spectrum and the like. Stimulus circuit 446 can be implemented as any suitable circuitry.

Microcontroller 447 of command input device 140 includes an input and an output. The input of microcontroller 447 is electrically coupled and in communication with stimulus circuit 446 and LO PWR circuit 280. The output of microcontroller 447 is electrically coupled and in communication with control circuit 290. Microcontroller 447 receives a command signal from stimulus circuit 446, generates an operational signal based on the logic within microcontroller 447 and passes the generated operational signal to control circuit 290. Microcontroller 447 can be implemented as any suitable logic circuit.

In operation, power strip 400 enables a user to control the power strip and determine when power is supplied to devices, such as, a personal computer or peripherals that are in electrical communication with controlled outlet(s) 150. In the same or a different embodiment, a user can control power strip 400 and determine when a user may be nearby using one or a number of active methodologies, such as, for example ultrasonic spectrum, radio frequency (RF) spectrum, light emitting diode (LED) spectrum, and the like. In other embodiments, a user can control power strip 400 and determine when a user may be nearby using one or a number of passive methodologies, such as, for example infrared spectrum, audio spectrum and the like. In one embodiment, power strip 400 enables a user to reduce power consumption of the devices in electrical communication with controlled outlet(s) 150 by allowing a user to completely shut power off to her devices until stimulus circuit 446 determines one or more specific criteria have been met.

FIG. 5 is a circuit schematic diagram illustrating an embodiment of an exemplary MOV protection circuit 500, such as, for example MOV protection circuit 260 of FIGS. 2-4 above. MOV protection circuit 500 performs the functionality as described in FIGS. 2-4 above by receiving raw power from a power source and providing protected, real power to the remainder of the elements within the circuit, such as, the additional elements described in FIG. 2-4, above. The concepts underlying MOV protection circuit 500 are known in the art, and therefore only certain portions of MOV protection circuit 500 will be described herein. MOV protection circuit 500 includes a line node NL, a neutral node NN and a ground node NG as well as numerous other nodes N51-N514. NL is in electrical communication with a line voltage. NN is in electrical communication with the neutral line. NG is in electrical communication with ground.

In FIG. 5, circuit breaker SW-Breaker is located between node NL and node N51, and thermal fuse F1 is located between node N51 and N52. Diode D4 includes an anode coupled to node N52 and a cathode coupled to node N53, and resistor R7 is located between node N53 and N54. Wire fuse J1 is located between node N52 and Node N55, thermal fuse F2 is located between node N55 and node N57, and MOV M1 is located between node N57 and node NN. Resistor R1 is located between node N52 and node N56, capacitor C1 is located between node N52 and node NN, MOV M4 is located between node N52 and node NN, and resistor R4 is located between node N52 and node NG. Resistor R2 is located between node N57 and node N58, and diode D1 includes an anode coupled to node N58 and a cathode coupled to node N56. Bipolar junction transistor (BJT) Q1 include a base coupled to node N58, an emitter coupled to node N56 and a collector coupled to node N510. Resistor R3 is located between node N57 and node N59, and LED1 includes an anode coupled to node N59 and a cathode coupled to node N510. Diode D2 includes an anode coupled to node N510 and a cathode coupled to node NN. MOV M2 is located between node N52 and node N513. LED2 includes an anode coupled to node N54 and a cathode coupled to node N511. BJT Q2 includes a collector coupled to node N511, a base coupled to node N512 and an emitter coupled to node NN. Resistor R5 is located between node N512 and node NG, resistor R6 is located between node N512 and node NN. Diode D3 includes a cathode coupled to node N512 and an anode coupled to node NN. MOV M3 is located between node NN and node N513; thermal fuse F3 is located between node N513 and node N514; and wire fuse J2 is located between node N514 and node NG.

In FIG. 5, capacitor C1 reduces unwanted signals or noise from external sources. MOVs M1, M2, M3 and M4 reduce unwanted voltage spikes to acceptable levels. Bipolar junction transistor (BJT) Q1 and associated components are a “crowbar circuit” to sense when MOV M1 is no longer providing protection and to completely and permanently disable the relocatable power tap, such as, power strip 200 in FIG. 2. BJT Q2 and associated components determine if power strip 200 is properly grounded or not and communicate the determination to a user through some type of user interface (e.g., if not properly grounded, light emitting diode (LED) LED2 lights up to show a fault). Resistor R6 counters the collector leakage current (Icbo) of BJT Q2. Diode D4 provides direct current (DC) power for the circuit as well as diode D3, which prevents a reverse bias voltage from biasing the base of Q2. In this embodiment, if a connection to ground is lost or was never present, resistors R4 and R5 function to pull the base of Q2 “high” thereby causing Q2 to conduct and supply power to the light emitting diode LED1 which when active indicates loss of ground to a user.

Although the circuit as detailed in FIG. 5 and described above is a typical solution for providing the above described functionality, the functions detailed and described may be implemented using different types of components. For example, the MOVs may be replaced with transient voltage suppressor (TVS) devices, discrete transistor circuits using integrated circuitry, or electromagnetic interference/radio frequency interference (EMI/RFI) suppression circuitry utilizing inductors, transformers and any combination of components to create the required suppression.

FIG. 6 is a circuit schematic diagram illustrating an embodiment of a portion of an exemplary system for providing a multi-outlet master/slave power strip incorporating an improved power supply and excluding an MOV portion. Power strip 600 in FIG. 6 is a detailed view of a portion of power strip 200 of FIG. 2, but for clarity, excludes the portion of power strip 200 disclosed and described as MOV protection circuit 500 of FIG. 5. Power strip 600 performs the functionality as described in FIG. 2 by receiving protected power, such as, from an MOV protection circuit (i.e., MOV protection circuit 260 of FIG. 2) and providing multi-outlet master/slave power strip functionality as also described in FIG. 2, above. Power strip 600 includes: master outlet 240, controlled outlet(s) 150, hi-power (HI PWR) circuit 270, low-power (LO PWR) circuit 280, sensing (SENSE) circuit 242, amplification (AMP) circuit 244 and control circuit 290. Power strip 600 includes a line node NL, a neutral node NN and a ground node NG as well as numerous other nodes N62-N620. NL is in electrical communication with a line voltage, and in one embodiment is substantially similar to node N52 in FIG. 5. NN is in electrical communication with the neutral line. NG is in electrical communication with ground. Elements numbered as in FIGS. 1 and/or 2 function in a substantially similarly way.

Master outlet 240 includes a plug receptacle for interfacing with a device power cord as well as three (3) inputs including a line input coupled to a line node NL, a neutral input coupled to node N61 and a ground input coupled to node NG. SENSE circuit 242 includes a current transformer (CT) that includes a primary winding having a first end coupled to node N61 and a second end coupled to node NN. CT additionally includes a secondary winding having a first end coupled to node NN and a second end coupled to node N62. SENSE circuit 242 is configured to sense when a device that is interfacing with master outlet 240 is drawing current and then provide a sensing signal (SENSE SIG) to AMP circuit 244 based on the current draw. In an embodiment, the neutral input of master outlet 240 passes through the core of SENSE circuit 242 and is coupled to the node NN. In some embodiments, when current is drawn by a device electrically coupled via the plug receptacle of master outlet 240, the current flows via a path that is electrically coupled to CT of SENSE circuit 242 and induces a small voltage in the secondary winding of CT, the SENSE SIG.

In FIG. 6, AMP circuit 244 includes a first operational amplifier (Op Amp) U1A that includes a non-inverting input coupled to node N62, an inverting input coupled to node N63, an output coupled to node N64, a DC power supply input coupled to node N65 (also called Vcc) and a DC return input coupled to node NN. Resistor R3 is located between node N63 and node N64, and resistor R10 is located between node N63 and node N66. Polarized capacitor C102 includes an anode coupled to node N64 and a cathode coupled to node N67. Op Amp U1B includes a non-inverting, input coupled to node N67, an inverting input coupled to node N68, an output coupled to node N69, a DC power supply input coupled to node N65 (also called Vcc) and a DC return input coupled to node NN. In one embodiment, Vcc is a fixed low power DC power signal. Resistor R102 is located between node N68 and node N69; resistor R103 is located between node N68 and node NN; and resistor R104 is located between node N67 and node NN. Diode D7 includes an anode coupled to node N69 and a cathode coupled to node N610. Polarized capacitor C4 includes an anode coupled to node N610 and a cathode coupled to node NN. Finally, diode D6 includes an anode coupled to node N611 and a cathode coupled to node N65.

AMP circuit 244 includes two operational amplifiers configured to receive a SENSE SIG from the secondary winding of CT and produce a driving signal that is provided to control circuit 290. In some embodiments, AMP circuit 244 includes two (2) operational amplifiers (U1A and U1B) which amplify the voltage signal (SENSE SIG) to produce an amplified control signal (CTRL SIG) and provide the CTRL SIG to control circuit 290. In an example and referring to FIG. 6, SENSE SIG is amplified by the circuit of U1A, R3, and R10 by a factor of about 61.6 to produce and intermediate control signal. Further to this example, only the AC component of the intermediate control signal is passed by C102 and impressed across R104. In this example, because there is no DC component, about half the AC signal is lost in the rail making the effective intermediate control signal voltage gain approximately 31. The intermediate control signal is then amplified by the circuit of U1B, R103, and R102 by a factor of approximately 29.6 with the result that the overall signal voltage gain is about 911 to produce the amplified control signal, CTRL SIG. In this example, the CTRL SIG voltage is peak-detected by the combination of C4 and D7.

In FIG. 6, control circuit 290 includes LED D101 including an anode coupled to node N611 and a cathode coupled to node N612; resistor R12 is located between node N612 and node N613; and resistor R13 is located between node N613 and node NN. Multi-bipolar junction transistor (BJT) circuit Q3 is configured as a Darlington pair and includes a base coupled to node N613, a collector coupled to node N614 and an emitter coupled to node NN. Diode D8 includes an anode coupled to node N614 and a cathode coupled to node N615. Relay circuit K1 includes a first end coupled to node N614, a second end coupled to node N615, a stationary normally open contact coupled to node NL and an armature moving contact coupled to node NL.

In operation, the CTRL SIG passes across both D101 and R12 to bias BJT circuit Q3 into conduction. Biasing Q3 turns on or closes relay/switch K1 which energizes controlled outlet(s) 150. In an example, relay/switch K1 is implemented as a single pole, single throw switch. In this embodiment, D8 absorbs counter electromagnetic fields (EMF) from relay/switch K1; R13 is used to counter Icbo from BJT circuit Q3; and D6 discharges C4 on shutdown of power strip 600.

In FIG. 6, HI PWR circuit 270 includes capacitor C100 located between node NL and node N617; resistor R100 is located between node N617 and node N618; and diode D100 includes an anode coupled to node N618 and a cathode coupled to node N615. Resistor R101 is located between node NL and node N617. Zenor diode ZD100 includes a cathode coupled to node N618 and an anode coupled to node NN, and polarized capacitor C101 includes an anode coupled to node N615 and a cathode coupled to node NN.

In operation, C100 is a reactive voltage divider which supplies a reduced current limited voltage to R101 and ZD100. Additionally, in this embodiment R100 functions as a bleeder resistor, and R101 provides additional resistance in the event of over-voltages. Further to the embodiment, ZD100 and D100 are configured to provide 24 volts for a half wave rectified power signal. Additionally, in this embodiment D100 is located and configured so that, during the opposite half cycle, C101 is not discharged into ZD100, which is configured to be forward biased. Further to the embodiment, C101 stores and smoothes out the energy required to run the control circuit 290. In an example, HI PWR circuit 270 supplies variable (high and low) DC power signals to control circuit 290 via node N615, and further supplies an AC power signal to relay circuit K1 via node NL.

In FIG. 6, LOW PWR circuit 280 includes a polarized capacitor C3, which includes an anode coupled to node N65 and a cathode coupled to node N66. Capacitor C2 is located between node N619 and node NL, and resistor R8 is also located between node N619 and node NL. Resistor R9 is located between N619 and N620. Zenor diode ZD1 includes a cathode coupled to node N620 and an anode coupled to node NN, and diode D5 includes an anode coupled to node N20 and a cathode coupled to node N65.

In operation, C2 is a reactive voltage divider that supplies a reduced current limited voltage to R9 and ZD1. Additionally, in this embodiment R8 functions as a bleeder resistor, and R9 provides additional resistance in the event of over-voltages. In an example, ZD1 and diode D5 are configured to provide 6.2 volts for a half wave rectified power signal. Additionally, in this embodiment diode D5 is located and configured so that, during the opposite half cycle, capacitor C3 is not discharged into diode D5, which is configured to be forward biased. Further to the embodiment, capacitor C3 stores and smoothes out the energy required to run the AMP circuit 244.

In the power supply portion of power strip 600, the two power circuits (HI PWR circuit 270 and LO PWR circuit 280) are substantially similar in design, but have different power values to supply to other portions of power strip 600. Utilizing a dual power supply methodology allows for a more efficient delivery of power (24V and 6.2V) to downstream active elements of power strip 600. The efficiency is realized as a single supply supplying dual voltages that are substantially different from what would be required by a resistive methodology to voltage divide the voltage down, thereby producing heat and wasting additional power.

Each of controlled outlet(s) 150 includes a plug receptacle for interfacing with a device power cord as well as three (3) inputs including a line input coupled to relay/switch K1, a neutral input coupled to node NN and a ground input coupled to node NG. Each of constant “on” outlet(s) 130 include a plug receptacle for interfacing with a device power cord as well as three (3) inputs including a line input coupled to node NL, a neutral input coupled to node NN and a ground input coupled to node NG.

FIG. 7 is a circuit schematic diagram illustrating an embodiment of a portion of an exemplary system for providing a multi-outlet controlled power strip incorporating an improved power supply and excluding an MOV portion. The power strip 700 in FIG. 7 is a detailed view of a portion of power strip 300 of FIG. 3, but for clarity, excludes the portion of power strip 300 disclosed and described as MOV protection circuit 500 of FIG. 5. Power strip 700 performs the functionality as described in FIG. 3 by receiving protected power, such as, from an MOV protection circuit (i.e., MOV protection circuit 260 of FIG. 3) and providing multi-outlet controlled power strip functionality as also described in FIG. 3, above. Power strip 700 includes: constant “on” outlet(s) 130, controlled outlet(s) 150, hi-power (HI PWR) circuit 270, low-power (LO PWR) circuit 280, control circuit 290, antenna 341, receiver circuit 343, logic circuit 345 and manual switch 348. In some embodiments, antenna 341 is configured as part of receiver circuit 343. Power strip 700 includes a line node NL, a neutral node NN and a ground node NG as well as numerous other nodes N71-N738. NL is in electrical communication with a line voltage, and in one embodiment is substantially similar to node N52 in FIG. 5. NN is in electrical communication with the neutral line. NG is in electrical communication with ground. Elements numbered as in FIGS. 1, 2 and/or 3 function in a substantially similarly way.

In FIG. 7, receiver circuit 343 includes an antenna 341 and receiver chip U1 as well as other elements that will be described below. Receiver circuit 345 includes antenna 341 that is coupled to node N71. Inductor L1 is located between node N71 and a radio frequency ground RFGND, and capacitor C3 is located between node N71 and node N72. Inductor L2 is located between node N72 and RFGND, and capacitor C5 is located between node N72 and RFGND. Capacitor C4 is located between node N72 and node N73, and inductor L3 is located between node N73 and RFGND. Receiver chip U1 includes: an antenna pin ANT coupled to node N73; a power supply pin Vdd coupled to node N75; a DO pin coupled to node N77; a CAGC pin coupled to node N78; a CTH pin coupled to node N79; a RO1 pin coupled to node N710; a RO2 pin coupled to node N711; and a RNG1 pin, a RFG2 pin, a SEL0 pin, a SEL1 pin, a SHDN pin, an NC pin and a GND pin coupled to RFGND. Resistor R1 is located between node N74 and RFGND. Capacitor C1 is located between node N75 and RFGND, and capacitor C2 also is located between node N75 and RFGND. Capacitor C7 is located between node N78 and RFGND, and capacitor C6 is located between node N79 and RFGND. Crystal Y1 is located between node N710 and node N711.

In FIG. 7, logic circuit 345 includes an address selector switch S1, logic chip U4, logic chip U3 as well as other elements. Switch S1 is an addressable selector switch and includes four (4) input pins that are coupled to GND and four output pins that are coupled to pins A2-A5 of decoder U4. In other embodiments, switch S1 may be configured to include more, or less, pins with a corresponding reduction or increase in associated pins on decoder U4. Logic chip U4 additionally includes: a power supply pin Vcc coupled to node N76; an OSC1 pin coupled to node N712; an OSC2 pin coupled to node N713; a D9 pin coupled to node N714; a D8 pin coupled to node N715; a VT pin coupled to node N725; and a Vss pin coupled to GND. Capacitor C9 is located between node N76 and GND. Resistor R2 is located between node N712 and node N713. U2A is a NAND gate logic chip having a first input coupled to node N714, a second input coupled to node N725 and an output coupled to node N716. U2B is a NAND gate logic chip having a first input coupled to node N725, a second input coupled to node N715 and an output coupled to node N717. Logic chip U3 includes: a Vcc pin coupled to node N76; an inverted PR pin coupled to node N716; a D pin coupled to an inverted Q pin of logic chip U3; a CLK pin coupled to node N720; an inverted CLR pin coupled to node N722; a Q pin coupled to node N721; and a GND pin coupled to GND. Capacitor C8 is coupled between node N76 and GND. U2C is a NAND gate logic chip having a first input coupled to node N719, a second input coupled to node N718 and an output coupled to node N720, where nodes N718 and N719 are at the same potential. Resistor R3 is located between node N718 and node N76, and capacitor C10 is located between node N718 and GND. Manual Switch 348 includes an output pin coupled to node N718 and a ground pin coupled to GND. Diode pair D1 include a first diode having an anode coupled to node N722 and a cathode coupled to node N717, and a second diode having an anode coupled to node N722 and a cathode coupled to node N723. Resistor R4 is located between node N722 and node N76. Switch power LED D3 includes an anode coupled to node N721 and a cathode coupled to node N719. U2D is a NAND gate logic chip having a first input coupled to node N724, a second input coupled to node N724 and an output coupled to node N723, a DC power supply input coupled to node N76 and a DC return input coupled to GND. Capacitor C11 is located between node N76 and GND. Capacitor C712 is located between node N76 and node N724, and resistor R5 is located between node N724 and GND. Diode pair D2 includes a first diode having a cathode coupled to node N724 and an anode coupled to GND and a second diode having a cathode coupled to node N725 and an anode coupled to GND. In one embodiment, U2 logic chips are implemented as NAND gates with Schmitt Triggers.

In operation, a user determines when the peripheral devices receiving power from controlled outlet(s) 150 should be enabled or disabled. The user sends an encoded signal to the unit to perform the on or off function. Antenna 341 receives the electromagnetic radiation and converts it into an electrical signal. Receiver circuit 343 selects or tunes the signal, amplifies it, and then recovers the digital signal embedded in the transmission. Receiver circuit 343 then supplies the digital signal to decoder U4 within logic circuit 345 which determines if the transmitted signal belongs to power strip 700 and the type of signal, such as, whether it is an on or an off signal. An on signal forces the flip/flop of logic circuit U3 to output a one, and an off signal forces the flip/flop of logic circuit U3 to output a zero. The switch S2, if pressed, changes the flip/flop to the next state. A one turns on LED D3, transistor Q1, and relay K1; which energizes the controlled outlet(s) 150. A zero turns everything off. The power supply comprises of two modules, one to generate power for the relay and one for the rest of the circuitry. This feature is part of the energy savings scheme.

Further to the above, the received electromagnetic signal is processed through a preselect/matching filter composed of L1-L3 and C3-C5. This filter matches the output impedance of antenna 341 to the input impedance of the receiver circuit 343. This process additionally helps to attenuate any out of channel signals resulting in pre-tuning the receiver. The signal is next passed into receiver chip U1 and is further tuned to a single frequency with a relatively narrow bandwidth, thus screening out most all other signals, resulting in obtaining the signal of interest. Receiver chip U1 amplifies this signal and utilizes a detection methodology to recover the embedded digital signal. C1 and C2 remove any signals from receiver circuit 343 that could find their way in from a power supply. Crystal Y1 provides a precise frequency used to run the tuning circuit. R1 is a zero ohm resistor and if removed allows the squelch feature of the radio to be used. C6 is used in the detection circuit of receiver chip U1 and stores a relative threshold value for receiver chip U1 to determine whether to output a logic one or a logic zero signal in the serial data output. CS is used in the Automatic Gain Control (“AGC”) circuit of the receiver. AGC is used to adjust the gain of the radio to a value fixed relative to the detector requirements for reliable output data.

The tuned signal is fed into decoder U4 which decodes this serial data into address and function. The address is checked against the value set on switch S1. If there is a match, then an on or off function is output depending on the match data, with an “on” output passing to port pin D9 of decoder U4 and an “off” output passing to port pin D8 of decoder U4. Resistor R2 sets an internal RC generated clock frequency to run the decoder U4. Capacitor C9 prevents power supply noise from leaving or entering decoder U4. Additionally, capacitor C8 and capacitor C11 perform the same function on ICs U3 and U2, respectively.

If decoder U4 recognizes a valid address, then pin VT is set “high” for the address time, which allows the function signal to pass through a transmission gate made up of U2A and U2B. If the signal is a “one,” it is fed directly into the flip/flop logic chip U3 preset (PR bar) pin and forces a “one” resulting in an “on” signal at the Q output. The opposite signal, in this case a “zero,” is fed into the D input of the flip/flop from the Q-bar output of logic chip U3. If a clock signal is fed into the CLK input of the flip/flop, then it will change state. Whenever a clock signal is received at the CLK input, the flip/flop will change state. The clock signal originates from U2C, which is a Schmitt triggered gate. The gate receives a signal from switch S2 every time the user presses the switch button of switch S2. The switch signal from switch S2 is de-bounced by resistor R3 and capacitor C10. When the user presses the button associated with switch S2, the controlled outlet(s) 150 change state. The “off” signal from the transmission gate (i.e., U2A and U2B) goes through an “OR” gate composed of resistor R4 and diode-pair D1. The “off” signal passes to the CLR-bar pin of the flip/flop. Receiving the “off” signal forces diode-pair D3, BJT Q1 and K1 of control circuit 290, and controlled outlet(s) 150 to switch “off.” Because there is an “OR gate” logic circuit within logic circuit 345, the other signal that forces everything to the “off” state is a power on reset. This signal is generated at power “on” by the Schmitt trigger gate U2D, capacitor C12 and resistor R5. One side of diode-pair D2 quickly discharges capacitor C12 to prepare capacitor C12 to help generate another power on reset signal if required. When flip/flop circuit is “on,” as defined by the Q output of integrated circuit (IC) U3 is a “one” or “high,” then current flows through the LED D3 causing it to light up and indicate that the controlled outlet(s) 150 are “on.”

In FIG. 7, HI PWR circuit 270 includes a resistor R8 located between node NL and node N726, and a capacitor C13 located between node NL and node N726. Full-wave bridge rectifier D5 includes a pin1 coupled to node N728, a pin2 coupled to node NN, pin3 coupled to node N726, and pin4 coupled to node N727. Inductor L4 is located between node N727 and node N729. Inductor L5 is located between node N728 and node GND. Capacitor C15 is located between node N729 and GND, Zenor diode Z2 includes an anode coupled to GND and a cathode coupled to node N729, and polarized capacitor C14 includes an anode couple to node N729 and a cathode coupled to GND.

In FIG. 7, LO PWR circuit 280 includes a resistor R9 located between node N30 and NL, and capacitor C16 is located between node N30 and NL. Full-wave bridge rectifier D6 includes a pin1 coupled to node N732, a pin2 coupled to node NN, pin3 coupled to node N730, and pin4 coupled to node N731. Inductor L6 is located between node N731 and node N733, and inductor L8 is located between node N732 and GND. Resistor R10 is located between node N733 and node N734, and capacitor C18 is located between node N733 and GND. Zenor diode Z3 includes an anode coupled to GND and a cathode coupled to node N734; polarized capacitor C17 includes an anode couple to node N734 and a cathode coupled to GND; and capacitor C19 is located between node N734 and GND. Low drop-out (LDO) regulator U5 includes an input pin coupled to node N734, an output pin coupled to node N76, and a ground pin coupled to GND. Capacitor C20 is located between node N76 and GND, and capacitor C21 is located between node N76 and GND. Resistor R11 is located between node N76 and node N735. Inductor L7 is located between node N76 and node N75. LED D7 includes an anode coupled to node N735 and a cathode coupled to GND. Inductor L9 is located between RFGND and GND.

Because HI PWR circuit 270 and LO PWR circuit 280 are similar but with different values to supply power as required, only one will be described in detail, as the other is functionally the same. Capacitor C16 of LO PWR circuit 280 is a reactive voltage divider which supplies a reduced voltage that is current limited to resistor R10 and LDO regulator U5. Resistor R9 is a bleeder resistor. Capacitor C18, inductors L6 and L8, resistor R10 and Zenor diode Z3 provide protection in the event of over voltages. Full-wave bridge rectifier D6 converts the incoming AC power to DC. Capacitors C17 and C19 further protect against surge voltages, help smooth the incoming rectified voltage and provide a broad band low impedance source for LDO regulator U5. LDO regulator U5 is an active low drop out regulator which provides a fixed voltage output for receiver circuit 343 and logic circuit 345. Capacitors C20 and C21 further smooth the output voltage and provide a required pole for LDO regulator U5. Inductors L7 and L9 isolate noise generated in the logic circuit from the radio. Resistor R11 and LED D7 are not used to generate power, but are an indicator circuit providing an indicator light when two conditions are both met. The two conditions are: (1) that constant “on” outlet(s) 130 have power; and (2) the MOVs of MOV protection circuit 500 in FIG. 5 have not failed.

Utilizing HI PWR circuit 270 and LO PWR circuit 280 as a two section power supply. design reduces power consumption of the power supply. In operation and understanding that power is a function of voltage times current, if a circuit will operate at some fixed current level, but at various voltages, then choosing the lowest voltage will use the least amount of power. Therefore, the low voltage supply (i.e., LO PWR circuit 280) is used to generate low voltage power for the radio and logic circuitry. This configuration uses the minimal amount of power for the low voltage circuitry because the reactive input power supply wastes no real power to generate the low voltage from the high voltage AC line power. The voltage for the relay is the high voltage supply (i.e., HI PWR circuit 270). Like the low voltage supply, the high voltage supply uses a reactive input to drop the line voltage to the voltage required for the relay. The high voltage supply is also a “soft” supply. That is, the voltage drops while a load current is drawn from the supply, providing even more of a power savings. The uniqueness of this approach as compared to the more traditional single power supply approach is that a power savings as high as 4 to 1 can be achieved over the traditional method.

In FIG. 7, control circuit 290 includes resistor R6 that is located between node N719 and node N736, and resistor R7 is located between node N736 and GND. Bipolar transistor Q1 includes a base coupled to node N736, a collector coupled to node N737, and an emitter coupled to GND. Zenor diode Z1 includes a cathode coupled to node N737 and an anode coupled to GND. Relay circuit K1 includes a first end coupled to node N737, a second end coupled to node N729, a stationary normally open contact coupled to node NL and an armature moving contact coupled to node NL.

In operations, current flows from logic circuit 345 to control circuit 290 through resistor R6, which limits the current for both diode-pair D3 and the base of BJT Q1. When current flow through resistor R6, BJT Q1 turns “on” and allows current to flow in the coil of relay circuit K1 of control circuit 290 causing relay circuit K1 to close its contacts and supply power to the controlled outlet(s) 150. If the flip/flop circuit of logic circuit 345 is “off,” as defined by the Q output of IC U3 is zero or “low,” then the LED D3 is not forward biased, and BJT Q1, relay circuit K1, and controlled outlet(s) 150 are “off.” When controlled outlet(s) 150 are “off,” there is no current flow into the base of BJT Q1 other than Icbo. Because the Icbo leakage current could turn the transistor on, resistor R7 drains any BJT Q1 Icbo to a safe level thereby preventing BJT Q1 from turning “on.” Only one half of diode-pair D4 (across the relay coil) is used for counter EMF when BJT Q1 turns off. Zenor diode Z1 is used to protect BJT Q1 against surge volts from the AC line that pass through the power supply.

FIG. 8 is a circuit schematic diagram illustrating an embodiment of a portion of an exemplary system for providing a multi-outlet controlled power strip incorporating an improved power supply and excluding an MOV portion. The power strip 800 in FIG. 8 is a detailed view of a portion of power strip 400 of FIG. 4 but, for clarity, excludes the portion of power strip 400 disclosed and described as MOV protection circuit 500 of FIG. 5. Power strip 800 performs the functionality as described in FIG. 4 by receiving protected power, such as, from an MOV protection circuit (i.e., MOV protection circuit 260 of FIG. 3) and providing multi-outlet controlled power strip functionality as also described in FIG. 4, above. Power strip 800 includes: constant “on” outlet(s) 130, controlled outlet(s) 150, hi-power (HI PWR) circuit 270, low-power (LO PWR) circuit 280, control circuit 290, stimuli circuit 346, logic circuit 347, and transformer T1. Power strip 800 includes a line node NL, a neutral node NN and a ground node NG as well as numerous other nodes N81-N820. NL is in electrical communication with a line voltage, and in one embodiment is substantially similar to node N52 in FIG. 5. NN is in electrical communication with the neutral line. NG is in electrical communication with ground. Elements numbered as in FIGS. 1, 2 and/or 4 function in a substantially similarly way. Transformer T1 includes a primary winding, a low-power secondary winding in electromagnetic communication with the primary winding and a hi-power secondary winding in electromagnetic communication with the primary winding. The primary winding of transformer T1 includes a first tap that is in electrical communication with node NL, and a second tap that is in electrical communication with node NN. Transformer includes additional elements that will be described further below. Additionally, stimuli circuit 346 is configured as a manual switch input circuit. In some embodiments, stimuli circuit 346 can be configured as any number of different stimuli circuits, such as, for example as a motion sensor circuit, a thermal sensor circuit, an ultrasonic sensor, and the like. FIG. 8 illustrates a line isolated power supply that may be utilized for safety concerns when part(s) of a circuit are accessible to the user.

In operation, a user and/or the device, depending on the input stimulus, determines when the peripheral devices should be supplied with power. In some embodiments the user presses a button to switch on the switched outlets and start a timer which then ends the sequence. In other embodiments, other input stimuli may completely automate the process, or the process may be completely manual, or some combination thereof. In one embodiment, power strip 800 operates as follows: a press of a switch sends an instruction signal to a microcontroller to turn on an LED and the circuitry associated with activating a relay, which energizes the controlled outlets; after a fixed time, the LED will start to blink on and off, if the button is not activated in the next short time window, the microcontroller turns the controlled outlets “off;” and if the button is pressed, the LED stays “on,” the relay remains “on” and the timer resets and restarts. In other embodiments, depending on the stimulus and the programming, different or all portions of the sequence may be automated. As with previous embodiments the power supply consists of two modules, one to generate power for the relay and one for the rest of the circuitry, and again this feature is part of the energy savings scheme.

In FIG. 8, logic circuit 347 includes a logic chip U2 and an electrical plug P1, as well as other elements that will be described below. In some embodiments, electrical plug P1 allows for the logic circuit 347 portion of power strip 800 to be removed from the circuit, if necessary. Logic chip U2 includes: an RA0 pin coupled to node N82; a RA1 pin coupled to node N83, a RA2 pin coupled to node N81, a RA3 pin coupled to node N84, a RA5 pin coupled to node N85, a power supply pin Vcc coupled to node N86, a RC2 pin coupled to node N87, a RC5 pin coupled to node N89, and a Vss pin coupled to GND. Programming pad ET1 is coupled to node N85; programming pad EP1 is coupled to node N86; programming pad EP2 is coupled to node N82; programming pad EP3 is coupled to node N83; programming pad EP4 is coupled to node N84; and programming pad EP5 is coupled to node GND. In some embodiments, pins RA0-RA3 are configured as programming pins, and pin RA4 is configured to provide clock information, such as, for example for programming support. Capacitor C8 is located between node N86 and GND. Resistor R11 is located between node N87 and node N88. LED D18 includes an anode coupled to node N88 and a cathode coupled to GND. Resistor R12 is located between node N89 and node N810. Electrical plug P1 includes a first pin coupled to node N86, a second pin coupled to node N810 and a third pin coupled to GND. In operation, each of the pins of electrical plug P1 mechanically and electrically coupled to a corresponding female connector located within jack J1 of control circuit 290.

In operation, logic chip U2 is implemented as a microcontroller that is programmed for the sequence through signals applied at programming pads EP1-EP5. A timing test signal can be measured at ET1 when test code is invoked. Capacitor C8 is used to help isolate digital noise from the power supply. At the start of the fixed time period described above, current flows through resistor R11 to LED D18 and the LED illuminates. The resistor, R11, limits the current. In one embodiment, logic circuit 347 is a separate module from the outlet strip and is electrically connected through plug P1 of logic circuit 347 and jack J1 of control circuit 290. In one embodiment, plug P1 is implemented as a 3.5 millimeter (mm) stereo phone plug, and jack J1 is implemented as a mating jack on power strip 800. In some embodiments, portions of plug P1 are soldered to pads E9-E11. In operation, plug P1 carries a signal used to power circuitry that activate controlled outlet(s) 150 and additionally provides power for logic chip U2, stimuli circuit 346, and LED D18. Further to the example, at the start of the timing sequence and at the same time logic chip U2 supplies current to LED D18, logic chip U2 additionally supplies current to resistor R12. Resistor R12 is in series with a signal wire in plug P1 and passes power to resistor R1, and hence, to control circuit 290.

In FIG. 8, HI PWR circuit 270 includes the hi-power secondary winding portion of transformer T1 that includes a first tap coupled to node N811, and a second tap coupled to node N812. Capacitor C6 is located between node N811 and node N813. Diode D12 includes an anode that is coupled to node N813 and a cathode that is coupled to node N814. Diode D13 includes a cathode that is coupled to node N813 and an anode that is coupled to GND. Diode D14 includes an anode that is coupled to N812 and a cathode that is coupled to node N814. Diode D17 includes a cathode that is coupled to node N812 and an anode that is coupled to GND. Polarized capacitor C7 includes an anode that is coupled to node N814 and a cathode that is coupled to GND. Resistor R10 is located between node N814 and GND.

In FIG. 8, LO PWR circuit 280 includes the low-power secondary winding portion of transformer T1 that includes a first tap coupled to node N815, and a second tap coupled to node N816. Capacitor C5 is located between node N815 and node N816. Diode D3 includes an anode that is coupled to node N815 and a cathode that is coupled to node N817. Diode D6 includes a cathode that is coupled to node N815 and an anode that is coupled to GND. Diode D7 includes an anode that is coupled to N816 and a cathode that is coupled to node N817. Diode D9 includes a cathode that is coupled to node N816 and an anode that is coupled to GND. Zenor diode D4 includes a cathode that is coupled to node N817 and an anode that is coupled to GND. Polarized capacitor C4 includes an anode that is coupled to node N817 and a cathode that is coupled to GND. Capacitor C4 is located between node N817 and GND. Low drop-out (LDO) regulator U1 includes an input pin coupled to node N817, an output pin coupled to node N86, and a ground pin coupled to GND. Polarized capacitor C1 includes an anode that is coupled to node N86 and a cathode that is coupled to GND.

In FIG. 8, power for power strip 800 is supplied from transformer T1. The input of transformer T1 protects the user from electric shock in the event contact is made between the user and exposed metal connected to the circuit. Transformer T1 has two secondary windings that are similar, but have different voltage values for supplying different levels of power, as required. For both power values supplied, transformer T1 efficiently reduces the input voltage on the primary winding of transformer T1 to some usable value. For the high voltage supply, capacitor C6 is a reactive current limiter to the full-wave rectifier diode bridge D12, D13, D14, and D17. Polarized capacitor C7 stores and smoothes the voltage supplied to the relay circuit K1. Resistor R10 bleeds excess energy from polarized capacitor C7.

The low voltage supply uses diodes D3, D6, D7, and D9 as the full wave rectifier bridge. The input to the bridge is shunted by C5, and the output of the bridge is shunted by D4. Both of these components are used to help attenuate any voltage surges. Capacitors C4 and C2 also help to mitigate surge damage. C4 and C2 have other functions. C4 and C2 help smooth the incoming rectified voltage and provide a broad band low impedance source for U1. U1 is an active low drop out regulator which provides a fixed voltage output for the micro controller and related circuitry. C1 helps to further smooth the output voltage and provides a required pole for the regulator.

In FIG. 8, control circuit 290 includes relay circuit K1, jack J1, as well as other elements that will be described below. Relay circuit K1 includes a first end coupled to node N814, a second end coupled to node N818, a stationary normally open contact coupled to node NL and an armature moving contact coupled to node NL. Diode D1 includes a cathode that is coupled to node N814 and an anode that is coupled to node N818. Bipolar transistor Q1 includes a collector coupled to node N818, a base coupled to node N819 and an emitter coupled to GND. Resistor R2 is located between node N819 and GND, and resistor R1 is located between node N819 and GND. Zenor diode Z1 includes a cathode couple to node N837 and an anode coupled to GND. Electrical jack J1 includes a first pin coupled to GND, a second pin coupled to node N86 and a third pin coupled to node N819. Jack J1 includes a first pin coupled to GND, a second pin coupled to node N86 and a third pin coupled to node N820. In operation, each of the female connectors of jack J1 mechanically and electrically receive a corresponding male connector located at electrical plug P1 of logic circuit 347.

In operation, plug P1 of logic circuit 347 passes power to resistor R1 of control circuit 290 via jack J1. Because resistor R1 is in series with the base of a BJT Q1, when the power is passed to resistor R1, BJT Q1 turns “on” which turns relay circuit K1 “on.” Relay circuit K1 then energizes the controlled outlet(s) 150. Resistors R12 and R1 limit the current to the base of Q1. R12 also helps to protect logic chip U2 from electrostatic discharge (ESD). Diode D1 is used to absorb the counter EMF generated by the magnetic field collapse from relay circuit K1 when BJT Q1 turns “off.” Resistor R2 is used to defeat the effect of Icbo if the logic circuit 347 is not electrically coupled to control circuit 290 via jack J1.

In FIG. 8, utilizing a two-tiered power supply design reduces power consumption within power strip 800. The reduced power consumption occurs as power is a function of voltage times current and if a circuit will operate at some fixed current level but at various voltages, then utilizing the lowest voltage will result in the least amount of power consumption. Therefore, a low voltage supply is used to generate low voltage power for logic chip U2 and associated circuitry. This technique uses the minimal amount of power for the low voltage circuitry because the transformer input power supply wastes little power to generate the low voltage from the high voltage AC line power. The voltage for relay circuit K1 is the high voltage supply. Like the low voltage supply, the high voltage supply uses a transformer input to drop the line voltage to the voltage required for the relay circuit K1. Unlike the low voltage supply, there is also a reactive current limiter, which wastes no real power. This is called a “soft” supply. The reactive current limiter takes advantage of an effect of relay circuit K1. In other words, as load current is drawn from the supply, the voltage drops, providing even more of a power savings. Additionally, although relay circuit K1 requires a high voltage to initially close its contacts and energize controlled outlet(s) 150 and uses the energy stored in capacitor C7 for initial engagement, relay circuit K1 can remain closed during operation using a lower voltage and therefore using less power. The uniqueness of this approach is that a power savings can be achieved over traditional methods.

FIG. 9 is a circuit schematic diagram illustrating an embodiment of a portion of an exemplary system for providing a multi-outlet controlled power strip incorporating an improved power supply and excluding an MOV portion. The power strip 900 in FIG. 9 is another embodiment of a portion of power strip 300 of FIG. 3. Portions of power strip 900 are substantially similar to portions of power strip 700 of FIG. 7, function in substantially similar ways and their elements will not be described further. The power strip 900 in FIG. 9 is a detailed view of another embodiment of power strip 300 of FIG. 3 and includes a single improved power supply but, for clarity, excludes the portion of power strip 300 disclosed and described as MOV protection circuit 500 of FIG. 5. Power strip 900 performs the functionality as described in FIG. 3 by receiving protected power, such as, from an MOV protection circuit (i.e., MOV protection circuit 260 of FIG. 3) and providing multi-outlet controlled power strip functionality. Power strip 900 includes: constant “on” outlet(s) 130, controlled outlet(s) 150, power supply circuit 975, control circuit 290, receiver circuit 343, logic circuit 345 and manual switch 348. Power strip 900 includes a line node NL, a neutral node NN and a ground node NG as well as numerous other nodes N91-N935. NL is in electrical communication with a line voltage, and in one embodiment is substantially similar to node N52 in FIG. 5. NN is in electrical communication with the neutral line. NG is in electrical communication with ground. Elements numbered as in FIGS. 1, 2, 3 and/or 7 function in a substantially similarly way.

In operation, a user determines when the peripheral devices should have power. The user sends an encoded signal to the unit to perform the power “on” or “off” function. Receiver circuit 343 receives the signal, tunes, amplifies and converts it into an electrical signal that is passed to logic circuit 345 for implementation. As described in FIG. 7 above, logic circuit 345 switches controlled outlet(s) 150 “on” or “off.” Manual switch 348 also switches the controlled outlet(s) 150 “on” or “off.” The power supply is a single module, which generates power for both relay circuit K1 and the low voltage circuitry of power supply circuit 975, described below

In FIG. 9, power supply circuit 975 includes a resistor R12 located between node N1 and NL, and capacitor C13 located between node N91 and NL. Full-wave bridge rectifier D7 includes a pin1 coupled to node RLYGND, pin2 coupled to node NN, pin3 coupled to node N91, and pin4 coupled to node N92. Inductor L4 is located between node N92 and node N93. Capacitor C15 is located between node N93 and RLYGND. Polarized capacitor C18 includes an anode coupled to node N93 and a cathode coupled to RLYGND, and Zenor diode Z2 includes an anode coupled to RLYGND and a cathode coupled to node N93. Inductor L6 is located between RLYGND and GND. Capacitor C17 is located between node N93 and GND. Low drop-out (LDO) regulator U5 includes an input pin coupled to node N93, an output pin coupled to node N96, and a ground pin coupled to GND. Capacitor C18 is located between node N96 and GND, and capacitor C19 is located between node N96 and GND. Resistor R11 is located between node N96 and node N94, and LED D9 includes an anode coupled to node N94 and a cathode coupled to GND. Inductor L5 is located between node N96 and node N95. Inductor L9 is located between RFGND and GND.

In FIG. 9, Resistor R15 and LED D9 are not used to generate power, but are an indicator circuit providing an indicator light when two conditions are both met. The two conditions are: (1) that constant “on” outlet(s) 130 have power; and (2) the MOVs of MOV protection circuit 500 in FIG. 5 have not failed. Capacitor C13 is a reactive voltage divider which supplies a reduced voltage that is current limited to the full-wave bridge rectifier D7. Resistor R12 is a bleeder resistor for capacitor C13. Resistor R16 is a fuse in the event that C13 shorted. Resistor R16 is shown as a zero ohm resistor, but in other embodiments Resistor R16 can be, for example, 100 ohms and 1 watt flameproof. Full-wave bridge rectifier D7 converts incoming AC power to DC power. Capacitors C15 and C16, inductor L4 and Zenor diode Z2 act to attenuate surge over-voltages. Capacitor C16 smoothes the rectified voltage from the bridge and stores the energy for use by relay circuit K1. Zener diode Z2 has a second function in which it establishes the maximum voltage across capacitor C16. Capacitor C17 and inductor L6 protect against surge voltages. Capacitor C17 also provides a high-frequency, low-impedance source for LDO regulator US allowing LDO regulator U5 to respond to fast changing loads. LDO regulator U5 is an active LDO regulator that provides a fixed voltage output for the receiver circuit 343 and logic circuit 345. Capacitors C18 and C19 help to further smooth the output voltage and provide a required pole for LDO regulator U5. Inductors L5 and L7 isolate noise generated in the logic circuit from the radio.

In FIG. 9, Zener diode Z2 generates the 24 volts needed to initially close relay circuit K1. This voltage is too high for the rest of the circuitry and is regulated down to 3.3 volts by LDO regulator U5. Unfortunately, the process of regulating the voltage down from 24 volts to 3.3 volts is inefficient and consumes real power in the LDO regulator U5 and in Zener diode Z2. To counteract this problem, the value of capacitor C13 keeps the inefficient power consumption at a minimum. When relay circuit K1 is engaged, the voltage across Zener diode Z2 reduces to approximately 7.6 volts and there is little to no power wastage in Zener diode Z2 as well as reduced power wastage within LDO regulator U5. This embodiment, while not saving as much power as the dual power supplies previously described, still saves power both in the design function and in the design itself.

FIG. 10 illustrates an example of a method 1000 of providing a selectable output AC power signal, according to an embodiment of the present invention. Method 1000 includes a process 1010 of producing an output AC power signal, a first DC power signal, and a second DC power signal at a power supply and based on a received input AC power signal. As an example, method 1000 can be a method associated with power strip 200 in FIG. 2, power strip 300 in FIG. 3, and/or power strip 400 in FIG. 4. In this example, the output AC power signal of process 1010 can be similar to the output AC power signal for constant “on” outlet(s) 130, controlled outlet(s) 150, and/or master outlet(s) 240. in this same example, the first DC power signal of process 1010 can be similar to the output of HI PWR circuit 270, and the second DC power signal of process 1010 can be similar to the output of LO PWR circuit 280. Also, the received input AC power signal of process 1010 can be similar to the input for power plug 120.

Next, method 1000 includes a process 1020 of producing a control signal at a control circuit based on a received command signal and the second DC power signal. As an example, the control signal of process 1020 can be similar to the signal transmitted from command input device 140 to control circuit 290 (FIGS. 2-4). In this same example, the command signal of process 1020 can be similar to the command signal generated within and transmitted within command input device 140 (FIGS. 2-4).

Subsequently, method 1000 includes a process 1030 of powering a switch circuit with the first DC power signal based on the control signal and the second DC power signal. As an example, the switch circuit of process 1030 can be a portion of control circuit 290 (FIGS. 2-4).

After process 1030, method 1000 includes a process 1040 of providing the output AC power signal to a load when the switch circuit is powered. As an example, the load of process 1040 can be similar to a device plugged in to any of constant “on” outlet(s) 130, controlled outlet(s) 150, or master outlet(s) 240 (FIGS. 2-4).

Next, in some embodiments, method 1000 can include a process 1050 of providing the output AC power signal to a constant power outlet when the output AC power signal is produced. As an example, the constant power outlet of process 1050 can be similar to constant “on” outlet(s) 103 (FIGS. 2-4).

Although the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made without departing from the scope of the invention. Additional examples of such changes have been given in the foregoing description. Accordingly, the disclosure of embodiments is intended to be illustrative of the scope of the invention and is not intended to be limiting. It is intended that the scope of the invention shall be limited only to the extent required by the appended claims. To one of ordinary skill in the art, it will be readily apparent that the devices and method discussed herein may be implemented in a variety of embodiments, and that the foregoing discussion of certain of these embodiments does not necessarily represent a complete description of all possible embodiments. Rather, the detailed description of the drawings, and the drawings themselves, disclose at least one preferred embodiment, and may disclose alternative embodiments.

Although aspects of the subject matter described herein have been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made without departing from the scope of the subject matter described herein. Accordingly, the disclosure of embodiments is intended to be illustrative of the scope of the subject matter described herein and is not intended to be limiting. It is intended that the scope of the subject matter described herein shall be limited only to the extent required by the appended claims. To one of ordinary skill in the art, it will be readily apparent that the devices and method discussed herein may be implemented in a variety of embodiments, and that the foregoing discussion of certain of these embodiments does not necessarily represent a complete description of all possible embodiments. Rather, the detailed description of the drawings, and the drawings themselves, disclose at least one preferred embodiment, and may disclose alternative embodiments.

All elements claimed in any particular claim are essential to the subject matter described herein and claimed in that particular claim. Consequently, replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims.

Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and/or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and/or limitations in the claims under the doctrine of equivalents. 

1. A relocatable power tap, comprising: a power supply circuit configured to receive an input AC power signal and produce an output AC power signal, the power supply circuit having a first stage and a second stage, the first stage of the power supply circuit configured to produce a first DC power signal and the second stage of the power supply circuit configured to produce a second DC power signal, a control circuit in electrical communication with the power supply circuit and configured to receive the output AC power signal, the first DC power signal and the second DC power signal, the control circuit including; a driver circuit, the driver circuit configured to receive the second DC power signal as a power source, the driver circuit further configured to receive a command signal and produce a control signal based on the received command signal; and a controlled switching circuit in electrical communication with the driver circuit and configured to receive the first DC power signal as a power source and to receive the output AC power signal, the controlled switching circuit further configured to receive the control signal from the driver circuit and provide the output AC power signal to a controlled outlet based on the received control signal; an input circuit, the input circuit coupled to the control circuit and configured to provide a command signal to the driver circuit of the control circuit, the command signal indicating whether a controlled outlet is to receive power; and at least one controlled power outlet, the at least one controlled power outlet having an input electrically coupled to the controlled switching circuit and an output configured to electrically coupled to an external device, the at least one controlled power outlet configured to receive the output AC power signal from the controlled switching circuit and provide the received output AC power signal to an external device.
 2. The relocatable power tap of claim 1, wherein the first stage of the power supply circuit is configured to receive the input AC power signal, produce the first DC power signal and provide the first DC power signal to the second stage of the power supply circuit, and the second stage of the power supply circuit is configured to produce the second DC power signal from the received first DC power signal.
 3. The relocatable power tap of claim 1, wherein the first stage of the power supply circuit is configured to receive the input AC power signal and produce the first DC power signal, and the second stage of the power supply circuit is configured to receive the input AC power signal and produce the second DC power signal.
 4. The relocatable power tap of claim 1, further comprising at least one constant power outlet, the at least one constant power outlet having an input electrically coupled to the power supply circuit and an output configured to electrically couple to an external device, the at least one constant power outlet configured to receive the output AC power signal from the power supply circuit and provide the received output AC power signal to an external device.
 5. The relocatable power tap of claim 1, wherein the input circuit includes a master power outlet having an input electrically coupled to the power supply circuit, a power output configured to electrically couple to an external device, and a command output electrically coupled to the control circuit and configured to provide a command signal to the driver circuit of the control circuit.
 6. The relocatable power tap of claim 5, wherein the control circuit additionally includes an amplifier circuit, the amplifier circuit configured to receive the command signal from the master power outlet, amplify the command signal, and pass the amplified command signal to the driver circuit of the control circuit.
 7. The relocatable power tap of claim 1, wherein the input circuit includes: an antenna, the antenna configured to receive a wireless signal; a receiver circuit coupled to the antenna, the receiver configured to receive the wireless signal from the antenna and produce a tuned signal based on the wireless signal; and a logic circuit coupled to the receiver circuit, the logic circuit configured to receive the tuned signal from the receiver circuit and produce a command signal based on the tuned signal.
 8. The relocatable power tap of claim 1, wherein the input circuit includes: a stimuli circuit, the stimuli circuit configured to receive input stimulus and produce an instruction signal based on the received input stimulus; and a logic circuit coupled to the receiver circuit, the logic circuit configured to receive the instruction signal from the stimuli circuit and produce a command signal based on the tuned signal.
 9. The relocatable power tap of claim 1, wherein the controlled switching circuit includes a switch selected from the group consisting of: an electromechanical switch, a solid-state switch, or a vacuum tube switch.
 10. A power supply for a relocatable power tap, comprising: a first power supply module configured to receive an input AC power signal; and a second power supply module; wherein the first power supply module and the second power supply module when coupled can be operative to provide an output AC power signal to an external load, a first DC power signal to a first internal load and a second DC power signal to a second internal load.
 11. The power supply of claim 10, wherein: the first power supply module includes a reactive voltage divider circuit, a rectifier circuit and a shunt regulator circuit, the first power supply module configured to receive the input AC power signal and produce the first DC power signal having at least a first state and a second state, wherein the amplitude of voltage associate with the first state of the first DC power signal is sufficient to activate the first internal load and wherein the amplitude of voltage associated with the second state of the first DC power signal is sufficient to maintain the activated first internal load; and the second power supply module including a voltage regulator circuit, the second power supply module configured to receive the first DC power signal and produce the second DC power signal.
 12. The power supply of claim 10, wherein: the first power supply module includes a reactive voltage divider circuit, a rectifier circuit and a shunt regulator circuit, the first power supply configured to receive the input AC power signal and produce the first DC power signal having at least a first state and a second state, wherein the amplitude of voltage associated with the first state of the first DC power signal is sufficient to activate the first internal load and wherein the amplitude of voltage associated with the second state of the first DC power signal is sufficient to maintain the activated first internal load; and the second power supply includes a reactive voltage divider circuit, a rectifier circuit and a voltage regulator circuit, the second power supply configured to receive the first AC power signal and produce the second DC power signal.
 13. The power supply of claim 10, further comprising: a transformer having at least a primary winding and plurality of secondary windings, the transformer configured to receive the first AC power signal and produce at least a first AC power signal and a second AC power signal; wherein: the first power supply module is reactively coupled and in electrical communication with a first secondary winding of the transformer, the first power supply module including a rectifier circuit and an energy storage circuit, the first power supply module configured to receive the first AC power signal and produce the first DC power signal having at least a first state and a second state, wherein the amplitude of voltage associate with the first state of the first DC power signal is sufficient to activate the first internal load and wherein the amplitude of voltage associate with the second state of the first DC power signal is sufficient to maintain the activated first internal load; and the second power supply module is in electrical communication with a second secondary winding of the transformer, the second power supply module including a rectifier circuit and a voltage regulator circuit, the second power supply module configured to receive the second AC power signal and produce the second DC power signal.
 14. The power supply of claim 10, wherein the first internal load is a switch circuit coupled to the first power supply module and the second power supply module, the switch circuit operable to provide the output AC power signal to the external load when activated by the first DC power signal.
 15. The power supply of claim 14, wherein the switch circuit is selected from the group consisting of: an electro-mechanical switch circuit, a solid-state switch circuit, or a vacuum tube switch circuit.
 16. The power supply of claim 10, wherein the second internal load is a control circuit coupled to the second power supply module, the switch circuit and an input circuit, the control circuit operable to control the switch circuit when powered by the first DC power signal.
 17. The power supply of claim 10, wherein the external load is configured as one or more controlled power outlets.
 18. A method for providing a selectable output AC power signal, comprising: producing an output AC power signal, a first DC power signal and a second DC power signal at a power supply and based on a received input AC power signal; producing a control signal at a control circuit based on a received command signal and the second DC power signal; powering a switch circuit with the first DC power signal based on the control signal and the second DC power signal; and providing the output AC power signal to a load when the switch circuit is powered.
 19. The method of claim 18, further comprising providing the output AC power signal to a constant power outlet when the output AC power signal is produced.
 20. The method of claim 18, wherein the switch circuit is selected from the group consisting of: an electromechanical switch circuit, a solid-state switch circuit, or a vacuum tube switch circuit.
 21. An apparatus, comprising: a power supply comprising: a first power supply module configured to receive a first input power signal and configured to provide a first DC output power signal at a first power level; a second power supply module electrically coupled to the first power supply and configured to provide a second DC output power signal at a second power level lower than the first power level; a first circuit receiving the first DC output power signal; and a second circuit receiving the second DC output power signal.
 22. The apparatus of claim 21, wherein the second power supply module is electrically coupled in series with the first power supply module such that the second power supply module receives the first DC output power signal as a second input power signal.
 23. The apparatus of claim 21, wherein the second power supply module is electrically coupled in parallel with the first power supply module such that the second power supply module receives the first input power signal. 